1. Field of the Invention
This invention relates to a system for streaming moving-image data, and to a streaming server and relay server that constitute this system. In this embodiment, “streaming” refers to the real-time transmission of received data and signifies a transmission that enables multiple users (client computers) to view the same scene when these multiple users receive data that is being transmitted.
2. Description of the Related Art
The transmission of very great quantities of moving-image data has become a reality with the ever increasing use of broadband over the Internet. However, the though line usage fee at the terminal of a broadband Internet line such as an ADSL (Asymmetric Digital Subscriber Line) is low, line usage fee on the server side that transmits a very large quantity of moving-image data is still high where broadband is concerned.
For example, assume that the data receive rate of a client computer is on the order of 1.5 Mbps (megabits per second). When moving-image data is transmitted from a server to 1000 of such client computers in this case, it is necessary that the speed at which data is transmitted from the server be made 15 Gbps. The usage fee of such a high-speed line is high.
It is necessary, therefore, that broadband be achieved on a terminal line while the band of a line on the server side is suppressed.